Estradiol and Testosterone Concentrations Among Thai Transgender Women in a Transgender-Led, Integrated Gender-Affirming Care and Sexual Health Clinic: A Real-World Analysis.

Purpose: Feminizing hormone therapy (FHT) is used by many transgender women as a pharmacological method to mitigate gender dysphoria. However, information on hormone concentrations among those who use FHT is lacking. We aimed to determine the proportion of Thai transgender women who were using FHT who had hormone concentrations within target ranges in a real-world clinic setting. Methods: Transgender women who attended Tangerine Clinic in Bangkok, Thailand, reported current use of FHT at clinic entry, and tested for both blood estradiol (E2) and total testosterone (TT) concentrations were included in the analysis. Hormone target concentrations were defined as 100-200 pg/mL for E2 and <50 ng/dL for TT. Results: Of 1534 transgender women included, 2.5% had undergone orchiectomy, and 524 (34.2%) had any hormones within target concentrations. Median (interquartile range) E2 and TT concentrations at baseline were 29 (14.3-45.3) pg/mL and 298.5 (22-646) ng/dL, respectively. Among those who had any hormones within target concentrations, 28 (1.8%), 11 (0.7%), and 485 (31.6%) had both hormones, only E2, and only TT within target concentrations, respectively. Among 1010 (65.8%) transgender women who had neither hormone within target concentrations, 989 (64.5%) and 21 (1.4%) had suboptimal and supraphysiological E2 concentrations, respectively. Among those who came to at least one follow-up visit (n=302), 165 (54.6%) transgender women managed to achieve or maintain either hormone within target concentrations. Conclusion: One-third of Thai transgender women who were using FHT had any hormones within target concentrations at baseline in this real-world setting study. Most transgender women who had neither hormone within target concentrations had suboptimal rather than supraphysiological E2 concentrations. More than half managed to achieve or maintain at least one hormone concentration within target concentrations at follow-up visits, suggesting a positive effect from attending a trans-led, integrated gender-affirming care and sexual health service.